How can PHP developers check if their server's IP address is on a blacklist or spam list, and what actions can be taken to address this issue?

To check if a server's IP address is on a blacklist or spam list, PHP developers can use online services or APIs that provide this information. If the IP address is indeed listed, actions can be taken such as contacting the blacklist provider to request removal, improving server security to prevent future listings, and monitoring the IP address regularly to ensure it stays off blacklists.

$ip_address = $_SERVER['SERVER_ADDR'];
$blacklist_check = file_get_contents("https://www.example.com/api/check_blacklist.php?ip=$ip_address");

if($blacklist_check == 'true') {
    // IP address is on blacklist, take necessary actions
    // Contact blacklist provider, improve server security, etc.
} else {
    // IP address is not on blacklist, continue with normal operations
}